docs: def instance(self, inst):
          """
          Called by __parse_xml_file in source_reader.
  
          """
  
          self.__inst = inst
  
          # use inst, to reduce attribute access time
          if isinstance(inst, declarations.declaration_t) and \
                  inst.location is not None and \
                  inst.location.file_name != '':
              inst.location.file_name = self.__files[inst.location.file_name]